1. Field of the Invention
The present invention relates to an apparatus and method for determining whether an image input through a scanner is a secure document (for example, paper money, etc.). More particularly, the present invention relates to an apparatus and method for determining whether a secure document exists or what kind of document is used in a short time.
2. Description of the Related Art
Conventional technology for preventing a secure document such as paper money from being copied uses a method of comparing various features (for example, a color and a specified pattern) of the secure document. Typically, techniques for preventing paper money from being copied extract a portion of the paper money as an input image, compare the main color of the input image with that of a predetermined pattern, and determine whether the input image is authentic paper money when the amount of the main color of the input image is substantially equal to the amount of the main color of the predetermined pattern.
The following procedures are performed in the conventional technology, to determine whether the input image includes the pattern of the paper money. First, a determination is made as to whether the pixels of the input image are included in a predefined color region and a binary bitmap composed of the pixels is made. Thereafter, a determination is made regarding the existence of a predefined image in the binary bitmap using a method such as correlation. If the predefined image exists in the binary bit map, a general image forming process stops.
A process of detecting a secure document must be performed in a limited amount of time. For example, when a sheet of paper money is produced, the detection of the paper money should be performed before the money is output. Conventional copy preventing technology detects a specific image of the input document which is likely to be identified and the image forming process stops or the output is blackened using a black toner after a portion of the input image is copied. If a process of detecting a partial image of the input image to be identified takes a long time, the effect of an image formation preventing function cannot be obtained. In order to solve this problem, a method of determining whether an input image is a secure document and outputting the image when the input image is not the secure document may be used. However, this process increases an image forming time.
Accordingly, there is a need for an improved system and method for determining whether an input image is a secure document and outputting the image when the input image is not the secure document.